Correct positioning of surgical instruments and implants, used in a surgical procedure, with respect to the patient's anatomy is often an important factor in achieving a successful outcome. In certain orthopaedic implant procedures, such as totals hip replacement (THR) or arthroplasty, total knee arthroplasty (TKA), high tibial osteotomy (HTO), and total shoulder replacement (TSR), for example, the optimal orientation of the surgical implant enhances initial function and the long term operability of the implant. A misaligned acetabular prosthetic socket, for example, can lead to complications such as dislocation of the hip joint, decreased joint motion, joint pain, and hastened failure of the implant.
Obtaining satisfactory orientation and positioning of a prosthetic implant is often a challenging task for orthopaedic surgeons. Currently, one technique for orientation and positioning is accomplished using purely mechanical instruments and procedures based on anatomical landmarks. For example, the desired anteversion for an acetabular cup prosthesis within an acetabulum is accomplished by using external landmarks associated with a patient's pelvis. These methods, however, are subject to misalignment caused by variations in these external landmarks. These variations can be caused, for example, by failing to orient the patient's pelvis in the assumed neutral position on the operating table. Other orientation and positioning techniques involve sophisticated computer imaging systems, which are typically expensive and complicated to use.
There is a need in the art for an improved device and method for obtaining accurate orientation of surgical instruments and implants during various orthopaedic repair and replacement procedures. There is a further need for a device that is simple and easy to operate.